Hi Greg:
You might want to look into IA's own proprietary upgrade, which includes an extrude-honed exhaust manifold & a different turbo (can't recall which one)---claims it's better than an RS2 upgrade. BTW, I'm going thru the same mental flailing---I'm sure I'll like the performance, but then it's 'tally up the investment' & think of the cars you could have bought for similar $.
Tom Daily
91 2K TQ 20V
90 V8 Quattro
86 928S Auto